The present invention relates to a cover for preventing chips therein from scattering. The cover is used for a trimmer having a rod at a front end of which a cutter rotating with a high speed is provided to trim grasses or the like.
In general, as trimming or cutting grasses, many small stones are existed on ground and therefore the stones and grasses trimmed may scatter toward an operator near cutter cords or the like of the trimmer. A protection cover is thus provided with a rod of the trimmer to prevent the chips such as small stones and grasses from scattering toward the operator.
In a prior art of a protection cover of the trimmer, a construction shown in JP-B 2-46653(Utility Model) is proposed. That is, as shown in FIG. 17, a trimmer head 43 rotating cutter cords 42 is disposed at a front end of an operational rod 41 and a protection cover 44 for preventing chips such as stones and grasses from scattering toward the operator is provided at the rear of the trimmer head 43. The protection cover 44 comprises an upper wall plate 45 positioned off to the upper of the trimmer head 43 and a protection plate 46 formed integrally to a rear end of the upper wall plate 45. A lower end 46a of the protection plate 46 is elastic and it is set at a position at which the lower end 46a is positioned closest to ground in accordance with the average height of both sexes. When grass trimming is operated as swinging the rod 41 right and left (in a direction shown by an arrow 47 in FIG. 17), the lower end 46a of the protection plate 46 may catch in or interfere with a projection such as a stubble or a large stone. In such a case, the lower end 46a of the protection plate 46 deforms to go over the projection.
The protection cover 44, however, has a problem shown below because the lower end 46a of the protection plate 46 is made of a one-piece plate.
When the lower end 46a catches in the projection such as a stubble or a large stone, the lower end 46a of the protection plate 46 is bent as a whole. That is, a part of the lower end 46a not facing the projection is also bent. A clearance between ground and the lower end 46a of the protection plate 46 hence becomes wider. It may occur that chips such as grasses trimmed or small stones inside the protection cover 44 are scattered toward the operator through the clearance. Operational efficiency of grass trimming by the trimmer with the conventional protection cover thereby is poor or not good due to the scattered grasses and small stones or the like.
Furthermore, the lower end 46a of the protection plate 46 gathers grasses trimmed and small stones on ground inside of the protection plate 46 when the rod 41 is swung right and left. The rotating cutter cords 42 hit the grasses and small stones gathered so that the number of the chips scattering and passing through the clearance between the lower end 46a of the protection plate 46 and the ground increases. Operational efficiency of grass trimming by the trimmer with the conventional protection cover thereby becomes worse.
There is a problem shown below in the conventional protection cover 44 because it can not adjust a vertical position of the protection plate.
Many of the grass trimming operations in a farm village are performed by women whereas many of the grass trimming operations in river side, road side or park are performed by men. In such a situation, a difference in height between men and women is big even in average thereof. It appears that the difference causes trouble in decreasing the effect of the protection cover. That is, the protection plate 46 is mounted at a position at which the lower end 46a is closest to the ground in reference to the average height of the both sexes. Therefore, the clearance between the lower end 46a of the protection plate 46 and the ground becomes wider in a case where person who is taller than the average. The chips scattered hence pass through the clearance and reach the operator. There is thus a problem of low operational efficiency in grass trimming.
To the contrary, in a case where person who is shorter than the average employs the trimmer, the lower end 46a of the protection plate 46 rubs on the ground to increase operational resistance so that the operational efficiency becomes worse and the operator gets more tired.